Running Edge Profile on Round Table Top

[Rod Sheridan]

Why would you not need a bearing bit with an index pin? I cannot see how you could do it without a bearing on the bit.

Hi George, the pin holds it a fixed distance from the cutter so the bit cuts a perfect circle, no wiggles, nothing.

A bearing follows all the imperfections, especially a router bearing that's very small, on a shaper the bearing would be 5 inches in diameter or more so it smooths out irregularities a little bit.

The index pin however generates a perfect circle................Regards, Rod.

[johnny means]

Typically, routing on a table is much less forgiving of imperfections in flatness.

[johnny means]

I think he might be refering to a pin used to ease entry into the cut.

[Charles Lent]

If you are trying to but a half round on the edge with a standard bearing end type 1/4 round roundover bit and then flip the table top over to round from the other side to get a half round on the edge of the table, you are going to have problems when rounding from the second side because the bearing will want to ride on wood that is no longer there, because you cut it away during the first pass. A special curved fence can be made from the scraps that you cut the round from by attaching these to your straight fence and then adjusting the fence position so that the bit cuts the 1/4 round on the second side without riding on the bearing. This will result in a full half round of the edge of the piece using 2 passes, one from the top and one from the bottom. If you think you can do it with a 1/4 round bit with a bearing, try it on scrap before doing the good piece and you will see what I mean. The bearing needs to be above the center of the 1/2 round and after the first cut there will be no wood in the right position for the bearing to ride on to properly position the bit to cut the same 1/4 round from the back side. It will cut deeper on the second side pass and leave a step in the middle of the rounded edge.

A non bearing 1/2 round bit (bull nose bit) of the right size, together with the same curved fence jig made from the curved off cuts will do it in just one pass, so long as the center of the bit just touches the center of the edge of the work and doesn't remove any material at that point. The rest of the bit will take care of the rounding both top and bottom in the one pass. They also make a bull nose type bit with a center bearing, but this bit leaves a flat in the middle of two quarter rounds and it will be a flat slightly wider than the thickness of the bearing.

A Starting Pin is just that...for starting a cut. It allows you to pivot the work around the pin to gradually cut into the work with the bit, to avoid dangerous grabbing of the work by the bit.

Make the half round fence jig from two corners of your scrap from making the round. It will let you guide the round edge into the bit and then rotate it to cut the shape of the bit in the edge of the work, without ripping the piece from your hands. The starting pin also works this way, but it is for beginning the cut on irregular shapes. A round fence works much better when edging round work of the same curve.

Charley

[George Bokros]

I am putting a cove and bead on the top edge of the table top. And yes, I am referring to exactly what Charles Lent is revering to as a starting pin.

I am concerned about the chip out and the burning of the cherry.

[Jim Morgan]

I am putting a cove and bead on the top edge of the table top. And yes, I am referring to exactly what Charles Lent is revering to as a starting pin.

I am concerned about the chip out and the burning of the cherry.

I believe that Rod was talking about using a centering pin as in a circle cutting jig, but if you are molding the top edge that probably won't work (unless you use a plug to cover up the hole for the pin). Taking an initial cut with an oversize bearing, whether with a handheld router or a router table with a starting pin, and then following up with a light finish cut should be your best bet.

[Rich Engelhardt]

I then glue that piece of wood in the center of the table with cardboard between it and the table.

That right there...
I'd make sure I used something substantial though for the trammel - 3/8" might be ok..
I tried to get by using 1/4" hardboard & it caused me to break 2 straight bits. (1/4").

One little tip about the glue for that cardboard buffer.
If you use Elmer's School Glue, you can wash it all off after you're done routing and you separate the pieces.
I normally use newspaper for that kind of - - what would you call it? buffer? - but I guess cardboard would work also.

[George Bokros]

I normally use newspaper for that kind of - - what would you call it? buffer? - but I guess cardboard would work also.

In high school we used the brown paper towels as the buffer when we did face plate turning on the lathe. This was a few years ago (I am couple decades past high school now) and the carpet tape had not been invented yet and there were no jaw chucks either.

[George Bokros]

I used my Dewalt 618 router with a new bearing guided Whiteside bit and accomplished it with no burning and now oops.

On to finishing now.